What was found
FLOOR SUPPORT STRUCTURE AT FS 559, RBL 28 TO RBL 42 HAS CORROSION. AIRCRAFT REMOVED FROM SERVICE. REMOVED CORROSION FROM FLOOR SUPPORT STRUCTURE AT FS 559, RBL 28 TO RBL 42, REF CRJ 200 REV (38) SRM 51-21-06. PERFORMED UT THICKNESS MEASUREMENT ON BLENDED AREA OF FLOOR SUPPORT STRUCTURE AT FS 559, RBL 28 TO RBL 42, THICKNESS .039. EVALUATED BLEND AND FOUND TO BE OUT OF LIMITS, REF CRJ 200 PART 4 REV 42 NDTM 51-00-001. UT GAUGE S/N 151136107 CAL DUE: 09-16-21. REMOVED FLOOR STRUCTURE AT FS 559, RBL 28 TO RBL 42, REF CRJ 200 REV (38) 51-42-06. FABRICATED FLOOR SUPPORT STRUCTURE FROM 7075 T6, .050 ALUMINUM SHEETING, REF DRAWING 601R31025-29, CRJ 200 REV (38) SRM 53-41- 43. INSTALLED FLOOR SUPPORT STRUCTURE AT FS 559, RBL 28 TO RBL 42, REF CRJ 200 REV (38) SRM 51-21-06.